1. Technical Field
The disclosed embodiments relate in general to a liquid crystal display device, and more particularly to a liquid crystal display device with switchable two-dimensional (2D) and three-dimensional (3D) display modes.
2. Description of the Related Art
Displays such as liquid crystal displays (LCDs) have been developed to provide three-dimensional (3D) displays in various forms and ranging from experimental displays in university departments to commercial products. Currently, most of 3D displays require the use of special headgear or glasses on the part of the viewer. Due to inconveniency of the use of headgear or glasses, many manufacturers have been studied and advanced towards the technology of autostereoscopic display.
Autostereoscopic displays, also known as “Naked eye 3D display”, are able to provide binocular depth perception without the hindrance of specialized headgear or filter/shutter glasses. Naked eye 3D displays have been demonstrated using a range of optical elements in combination with an LCD including parallax barrier technology and lenticular optic technology to provide stereoscopic vision. LCD including parallax barrier technology is taken for illustration as below.
Generally, the parallax barrier has optical apertures aligned with columns of LCD pixels. A parallax barrier could be a sheet or an electro optic panel with fine slits to separate the light pathway of spatial images into images for left eye and right eye, and this reconstructed scene of the left eye image and right eye image is perceived as 3D images by the observer. FIG. 1A is one of conventional 3D displays with parallax barrier. A parallax barrier 15 is positioned in front of a display panel 11, and set between human eyes and the display panel 11. The backlight module 13 emits light. The parallax barrier 15 with transparent and opaque strips limits the pixels only radiate light in directions seen by the left eye or right eye. In the accurate alignment between the backlight module 13 and the display panel 11, the left eye and the right eye of the observer would receive images on the odd numbered pixels and even numbered pixels, respectively. When different images are displayed on the odd numbered pixels and even numbered pixels of the display panel 11 and received by the left eye and the right eye correspondingly, it is capable of conveying depth perception to the viewer and providing stereoscopic vision by fooling the human brain.
FIG. 1B is another conventional 3D display device with parallax barrier. In FIG. 1B, the parallax barrier 15′ is positioned behind the display panel 11, and set between the backlight module 13′ and the display panel 11′. The transparent and opaque strips of the parallax barrier 15′ are still able to partially block the light emitted from the backlight module 13′, and only transparent strips of the parallax barrier 15′ allow penetration of light, thereby achieving the naked eye 3D displaying effect.
Generally, the naked eye 3D display device possesses 2D/3D switchable function. To switch the 2D display mode and 3D display mode of display device, the pattern of transparent and opaque interlaced strips of the parallax barrier 15 or 15′ as shown in FIG. 1A or FIG. 1B has to be disappeared. Most of the 2D/3D switchable 3D displays adopt electro optic panel with fine and vertical stripes as a barrier module. When the display device is in 2D display mode, the barrier module is turned off to allow the full penetration of the light from the backlight module. When the display device is in 3D display mode, the barrier module reveals the pattern of transparent and opaque interlaced strips. However, this naked eye 3D display device requires two display panels, which is bulky and expensive.